[PATCH STABLE] doctest: convert matcher root to native path

[Augie Fackler]

> On Jul 28, 2018, at 03:48, Yuya Nishihara <yuya at tcha.org> wrote:
> 
> # HG changeset patch
> # User Yuya Nishihara <yuya at tcha.org>
> # Date 1532763395 -32400
> #      Sat Jul 28 16:36:35 2018 +0900
> # Branch stable
> # Node ID 39885c84a7c1fa65637d281188c51de06d9c0997
> # Parent  5b3b74e4b21442777f741df60fd81e52e220a182
> doctest: convert matcher root to native path

Queued for stable, thanks.